Refrigerating apparatus



Feb. 15, 1944. J, R- HQRNADAY 2,341,781

REFRIGERATING APPARATUg Filed Nov. so, 1939 4 sheets-sheet 1 J. R. HORNADAY 2,341,781

REFRIGERATING APPARATUS Feb. 15, 1944.

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Feb. 15, 1944.

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REFRIGERATING APPARATUS Feb. 15, 1944.

Filed Nov. 30, 1939 4 Sheets-Sheet 4 f3.7 CLUTCH :5

VALVE FUEL PUMP Patented Feb. 15, 1944 UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS James R. Hornaday, Dayton, Ohio, assigner to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application November 30, 1939, Serial No. 306,913

10 Claims. (Cl. 257-3) This application relates to refrigeration and more particularly to an air conditioning system for railway cars and other vehicles.

An object of this invention is to provide an air conditioning system which may be energized from a prime mover of the internal combustion type and which may be automatically controlled by simple and elcient electrical controls.

A further object of this invention is to provide an air conditioning system which may be energlzed from a prime mover of the internal combustion type which will provide both heating and cooling to an enclosure under a system of controls which provide variable inside temperatures as modified by outside temperatures, and which outside temperature controls are further modifled by other outside controls to further modify the inside controls; all of which tends to give the most comfortable inside temperatures in all ranges of outside temperatures.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a vertical cross section of a portion of a railway car showing the preferred location of some of the elements of the air conditioning system;

Fig. 2 is a cross section taken along the line 2-2 of Fig. 1;

Fig. 3 is a diagrammatic representation of the air conditioning system as applied to a railway car; but the locations of the elements have been altered slightly for a. better disclosure of the system;

Fig. 4 is a wiring diagram to disclose the operation of the various electrical controls for the system;

Figs. 5 and 6 combined show the same wiring diagram which is shown in Fig. 4 on an enlarged scale and includes means for indicating which switches are operated by each solenoid.

THE REFRIGERATION SYSTEM The refrigeration system preferably includes a compressor |00, a condenser |0|, an evaporator |02 in refrigerant flow relationship. The evaporator may be provided with an expansion valve |03 tending to open whenever the refrigerant pressure in the evaporator falls below a predetermined limit. This valve |03 is modified by a thermostatic bulb |04 placed near the outlet of the evaporator which tends to throttle or close the valve |03 whenever the proper refrigerating effect reaches the bulb |04.

A liquid refrigerant solenoid control valve |32 is placed in the liquid refrigerant line |32a as a primary control of the liquid refrigerant flowing to the evaporator |02 through the expansion valve |03. The valve |32 is opened and closed by temperature responsive controls positioned within the car to cycle the refrigeration effect of evaporator 02, the operation of which will be hereinafter more fully explained. When the liquid refrigerant line |32a is closed by the valve |32 to stop the ow of refrigerant to the evaporator |02, a by-pass valve |41 automatically opens to permit the flow of a small amount of refrigerant, through the by-pass line |4la, to the compressor. The valve |4'l is of the usual automatic expansion type which is set to open when the suction pressure falls to some relatively low predetermined pressure and will open only when valve |32 is closed. This by-pass line l4la permits the compressor |00 to be operated continuously, by the internal combustion engine, whether refrigeration is needed or not, without overheating the liquid refrigerant expanding through the by-pass absorbing the heat of friction of the compresser.

The refrigerant is compressed at the compressor |00, condensed at the condenser |0I, expanded at the evaporator |02 and returned to the compressor |00 in a cycle well known in the air conditioning art.

The condenser |0| is provided with a fan |22 driven by an electric motor |23.-

The air to be conditioned within the car is circulated by a blower |24 driven by a blower motor |25. Air is drawn from the interior of the car |26 through the recirculating air inlet |21 and from the exterior of the car through the fresh air inlet |28. The air is then discharged into the interior of the car through the outlet or distributing means |29.

THE POWER SOURCE The power source for the air conditioning system may be an engine of the internal combustion type, such as a Diesel, kerosene or gasoline internal combustion engine. The specic disclosure in this application is for a Diese1 engine; although it is to be understood that the system can be varied to use a kerosene or gasoline engine. The Diesel engine is indicated at |05. It is provided with the usual water cooling jacket connected to a water cooling radiator |06. While the cooling water may be arranged to circulate by convection, it is preferred to provide a water pump driven by the engine |05, which causes water to circulate between the water jacket of the engine and the radiator |06 In addition, the water may be circulated to a reheat coil |01 which provides heat radiation surface for the hot water from the engine during certain periods of operation of the system, the function of which will be hereinafter more fully explained. The engine may be provided with a starter |08, which may be an electric motor geared by the usual starter mechanism to the flywheel |09 in such a manner that the starter |08 is connected to the flywheel when energized, and is disconnected after the engine attains a proper speed. The engine is further provided with a fan for circulating air through the radiator |06.

Ihe engine is also provided with other well known appurtenances such as a fuel tank connected by a line ||2 leading to a fuel injector and throttle control mechanism upon the engine. as is well known in Diesel practice. The fuel line ||2 is provided with a solenoid valve ||3 for controlling the now of fuel to the engine. An automatic throttle ||4 is provided on the engine and is placed under the control of a centrifugal governor for maintaining the proper speed of the engine under all load conditions. 'Ihe engine is provided with the usual fuel injecting pump mechanism for feeding the fuel to the engine under control of the automatic throttle. An auxiliary pump ||5 is provided for injecting fuel into the wind box of the engine for starting the engine under unusually cold conditions. The pump ||5 pumps fuel from the line |l2 into the wind box l I6 where the fuel is ignited by a spark plug ||1. Ignition of the fuel in the wind box heats the air entering the engine and thus insures ignition of the fuel charges injected into the cylinders.

The wind box ||6 is also provided with a control ||8 responsive to the pressure of the air in the box H6. The control H8 includes a switch which, when the air pressure has been built up by the speed of the engine to the proper degree, disconnects the starter and connects the clutch ||9 to cause the engine |05 to drive a generator |20, and the compressor |00. The compressor |00 is driven from the generator through the medium of belts 2|. The pressure of the air in the wind box ||6 is created by an air pump (not shown) driven by the engine in such a manner that the pressure in the box ||6 is proportional to the speed of the engine.

THE VALVES, THERMos'rATs, Ero.

Valves, thermostats, etc., are provided in the system for the proper functioning of the same, but before describing the functions of these various elements, the general construction of the elements is now described.

Mercury thermostats or thermometers are provided which open and close an electric circuit by means of a mercury coliunn rising and falling within a sealed tube and thus making contact with electric terminals extending through the walls of the tube into the path of the column of mercury. These mercury thermometers are indicated at 19, 15, 12, 18, 14, 1|, 10, 80, 90, |0, 60, 12A, 12B, 1|A and 60A.

Solenoid valves are used which open or close when the solenoid of the valve is energized. Such valves are indicated at |30, |3|, |32, |33 and |34. Valves |3|, |32, |33 and |34 are opened when the solenoid is energized. Valve |30 is closed when the solenoid is energized.

Heat-operated valves are used. These valves are heated by electric resistances. and when so heated, are closed. These valves are indicated at |35, |36, |31 and |38.

Electric relays are provided for making and breaking electric circuit, and include a solenoid and movable contact or contacts. In Fig. 4, the solenoid portion of any relay is indicated by a winding symbol. The movable contact or con tacts are shown by horizonal lines adjacent two small circles. The two small circles indicate the stationary contact or contacts which cooperate with the movable contact or contacts to open or close an electrical circuit. A designating letter or letters indicate each ofthe electric solenoid windings. Immediately following the letter or letters, a numeral or numerals are placed to designate the movable contact or contacts operated by such solenoid. 'I'he designating letter for each of the relay solenoids, together with a numeral, will identify the contact or contacts operated by that particular relay solenoid. Thus, the designating character of the solenoid indicates the number of contacts operated thereby, while the designating letter plus a numeral indicates each of the contacts operated thereby. Each of the contacts is correctly identified. For example, the symbol B"-|2-3 indicates a solenoid which operates three contacts. These contacts are designated respectively as B-I; B2; and B-3. The contacts B-| and B-2 are opened when the solenoid is energized, while the contact B-3 is closed when the solenoid is energized.

Further, each of the movable contacts of the relays is so positioned with respect to its stationary contacts that upon deenergization of the relay coil, the movable contact will fall to open or close electric circuit through the stationary contacts according to whether the movable contact is positioned above or below the stationary contacts. Energization of the relay coil moves the movable contacts upwardly with like result.

Resistances |39 are inserted in the circuits to reduce the current value and balance the potential across the contacts of the mercury tubes to prevent arcing at that point. These resistances |39 are used when the controlling mercury tube is shunted across the solenoid of the relay. The resistances |40 are for a similar purpose, but are used where the reley solenoid is in series with the mercury tubes. These resistances |40 provide surge current protection to the mercury tubes in the series circuit, tending to maintain a constant voltage through the mercury tubes when contact is made or broken; the resistances absorbing the current surge to prevent arcing or boiling of the mercury.

As shown in Figs. 3 and 4, the reference numeral 200 designates those thermostats which are located in the return air duct and which therefore respond to the temperature of the air inside the enclosure. Reference character 202 designates those thermostats which are located in the fresh air duct and which therefore respond to the temperature of the outside air. A third group of thermostats, located adjacent the floor of the conditioned space, has been designated by the reference numeral 204.

To describe a typical operation of an electrical control, reference is made to the upper part of Fig. 4. For example, when the temperature adjacent the tube 12 is rising, and reaches a temperature of '12 F., the contacts of tube 12 will be bridged, providing electric circuit therethrough. If the contact A-2 is in a lower position. an electrical circuit is made across the battery through disabling mercury tube 12, and if contacts B-2,.

D-2 should be in their lower positions, when the temperature reaches 75 F., the tube 'l5 makes a circuit across the battery and shunts the solenoid RH with a similar result. Likewise, if tubes 12 and 15 should be disabled and contacts C-2 should be closed, tube 19 can control the solenoid RH? and its contact by making and breaking a circuit across the battery.

THE AIR CONDITIONING SYSTEM The operation of the air conditioning system is regulated by means of temperature responsive controls positioned within the car, which controls are modified in their operation by the temperature outside the car. When the outside temperature is suiiiciently high to require a reduction of the temperature of the air inside the car below the temperature outside the car, the air conditioning system is so regulated as to provide a gradual increase of inside temperatures when the outside temperature increases; the inside temperature, however, increases at a much slower rate than the outside temperature. Also, when the outside temperature falls suiliciently low. the air conditioning system will supply heat to the air either from the Water system of the internal combustion engine or the usual steam supply on the train, or both. On cold days, higher inside temperatures are produced than on mild days. At all times, however, both refrigeration and heating systems may be rendered effective by the inside temperature controls, regardless of the temperature outside the car. For example, if the car should become too cool on a warm day, heat will be supplied alone or at the same time refrigeration is being supplied by the air conditioning system to raise the car temperature, or vice versa if the car temperature should become too warm on a cold day, refrigeration will be supplied alone or at the same time heat is being supplied by the air conditioning system to reduce the temperature of the air within the car. Thus, it can be seen that the system is not merely a heating or cooling system, but is a system for regulating the temperature inside the car at a constant level; the temperature level being selected according to the conditions prevailing outside the car. Mercury tubes are placed in a position to be responsive to the temperature inside the car for certain controls, and other mercury tubes are placed in a position tO be responsive to temperatures outside the car to modulate the inside controls.

On the warmest days, the air is cooled by the evaporator |02 alone. When the outside temperature falls to a less warm zone, evaporator |02 is operated, but its eiect is counter-balanced in part by the reheat coil |01. Then, as the outside temperature falls into a cold zone, the air is heated by reheat coil |01 alone, or supplemented by steam coil MI, it being understood that under all conditions, the effect of heat or refrigeration is always available to temper the effect of the other The reheat Reheat is generally obtained from the water system of the engine |05. 'I'he reheat coil |01 and radiator |0|i` are placed in parallel ow rela- 75 tonship with each other and in series with the jacket of the engine. The valves |30 and |3| are used to control the ow of hot water through one or the other of these coils. When necessary, as when the refrigeration system is being operated by the generator |20 acting as a motor, reheat can be produced by the supplementary steam coil |4| with the same result as reheat obtained from coil |01.

OPERATION UNDER DIFFERENT OUTSIDE CONDITIONS The electrical system of Fig. 4 is shown under conditions where the outside temperature is slightly below 70 F., but above 60 F. A master switch M is provided, which is closed whenever it is desired to place the system in readiness for operation, and which may be opened to disable all of the electrical system except the necessary steam valves for the floor heat under yard conditions. The engine is idle, but the system is in readiness for operation since the master switch M is closed. 'I'he operation of the system under various outside conditions will now be described.

Operation at 90 F. outside temperature When the outside temperature is 90 F., or above, refrigeration is produced in evaporator |02 and, if necessary, reheat is provided. The inside controls 19 and 18 are placed in command of the air conditioning system and tend to maintain the temperature inside the car between 79" F. and 78 F.

The above result is produced because the mercury columns in mercury tubes 10, 80 and 90 are all in contacting position. The closing of the circuit through disables the controls 10 and 80 because the deenergization of solenoid C opens contacts C-3 and C-4. In addition, the contacts C-I and C--2 are closed to place mercury tubes 11 and 18 in command of relays RH and LL. The controls 1|, 12, 14 and 15 are disabled because of the disabling of controls 10 and 80 which, in turn. causes energization of solenoids A and B, with the consequent opening of contacts A-|, A-2. B-I, B--2 and B-3. Contacts C-5 and C-G are also open at this time to break circuit through mercury tubes 14, 15.

With the controls set as above, and with the engine and the refrigeration system operating (the same having been started as hereinafter described), the full refrigeration capacity of the system is placed in operation on the air being circulated by the blower |24. If the temperature in the car is above 79 F., reheat is prevented because relay RH is deenergized, opening contact RH-l and deenergizing valves |30 and |3I. Valve |3| is closed when deenergized, thereby preventing circulation of hot water through reheat coil |01. If the temperature inside the car should continue to fall and reach a point between 78 F. and 79 F., relay RH is energized, thus closing contacts RH-I and energizing solenoid valves |30 and |3I. The energization of valves |30 and |3| opens -valve |3| and closes valve |30 thus shifting the flow of hot water from the engine to the reheat coil |01 to produce reheat in coil |01, thus tending to neutralize, to some extent, the refrigerating effect of the evaporator |02.

If the temperature inside the car should continue to fall, and fall below 78 F., refrigeration would be stopped entirely. Electric circuit through mercury tube 18 will be broken, thus deenergizing solenoid relay LL which, in turn, opens contact LL-l. The opening of contacts LL-I deenergizes and closed liquid refrigerant valve |32 and stops the operation of condenser fan |23, thus stopping refrigeration. Heat alone will now be supplied to the circulating air in the car until the temperature again rises above 78 F.

Operation when outside temperature is between 80 F. and 90 F.

When the outside temperature is at 80 F., but below 90 F., refrigeration is produced, with or without necessary reheat; but the air conditioning system is placed under the control of inside mercury tubes 14 and 15, with a consequent tendency to maintain the temperatures inside the car between 74 F. and 75 F.

The above results are produced because as the outside temperature falls below 90 F., circuit will be opened through mercury tube 90, thereby energizing relay C, closing contacts C-3, C-4, C-5, C-6 and opening contacts C--I and C-Z. This places mercury tube 80 in control. The closing of the circuit through mercury tube 80 deenergizes relay B, with the consequent closing of contacts B-I and B-Z and opening B-3. The opening of contacts B-3 disables control 10.

If the temperature inside the car is above 75 F., the circuit through mercury tube 15 is closed, with the consequent prevention of reheat by the deenergization of relay RH and consequent closing of valve I3|. If the temperature inside the car should then fall between 74 F. and 75 F., refrigeration with reheat is produced by the opening of the circuit through tube 15 and the maintenance of the circuit through tube 14 in the closed position. If the temperature inside the car should continue to fall below 74 F., refrigeration is stopped by the opening of the circuit through tube 14, with the consequent closing of liquid refrigerant valve |32 and the stopping of condenser fan |23.

Operation when outside temperature is between 70 F. and 80 F.

When the outside temperature is at or above 70 F., but below 80 F., refrigeration is produced with or without reheat with a tendency to maintain inside temperatures between 71 F. and '12 F. under the control of tubes 1| and 12.

The above results are obtained because the circuit through tube 10 is closed, and the circuits through tubes 80 and 90 are opened. The opening of the circuits through tubes 80 and 90 places the tube 10 circuit in control of the air conditioning system. As the outside temperature fell and opened the circuits through tubes 80 and 90, the contacts B-3 and C-3 were closed and the relay A was deenergized, with the consequent placing of contacts A-I and A-2 in the deenergized position. In addition, the opening of the circuits tubes 80 and 90 disabled controls 14. 15, 18 and 19.

If the temperature inside the car is above 72 F., refrigeration is produced with or without reheat under the control of controls 1| and 12. As both of these circuits are closed, refrigeration is produced without reheat. thus produced tends to lower the temperature in the car until it is below 72 F. and above 71 F., refrigeration with reheat is produced by the consequent opening of valve |3| and closing of valve I 30.` If the temperature should continue to fall and fall below 71 F.. refrigeration is stopped in the same manner hereinbefore described.

As the refrigeration Operation when outside temperature is between 70 F. and 60 F.

When the outside temperature is below 70 F.. but above F., the air conditioning system is placed under the control of inside thermostats 14, 15, and the reheat coil |01 and evaporator |02 are controlled in a manner tending to maintain the inside temperature between 74 F. and 75 F.

The above results are obtained due to the opening of the circuits through tubes 10, 80 and 90. The opening of the circuit through 10 energizes relay A, with the consequent raising of contacts A-l and A-Z to a position where they close upon the circuits of thermostat tubes 14, 15, thereby placing them in control. Thus, as the outside temperature falls below F., the temperature range inside the car is raised from 71 F.-72 F. range to 74 F.75 F. range to compensate for the lower outside temperature.

If the temperature inside the car is above 75 F., as previously described, refrigeration alone is produced; if between 74 F. and 75 F., refrigeration with reheat is produced; while if below 74 F., reheat alone is produced.

Operation when outside temperature is between 60 F. and 10 F.

When the outside temperature falls below 60 F., but is still above 10 F., the evaporator |02 and reheat coil |01 continue under the control of inside thermostats 14, 15; but in addition, supplementary heat may be provided at the coil |4| and the floor heat coils |42, |43 and |44.

Tube 60 is responsive to outside temperatures, while tube 12A is responsive to oor temperatures in the car. As long as the outside temperature is above 60 F. and the car floor temperature is above 72 F., supplementary heat is not required. However, when both outside and inside temperatures fall below the above respective values, supp lementary heat will be required. The tubes 60 and 12A are placed in parallel, electrically, so that the conditions of both must be met before supplementary heat is available.

When the outside temperature falls below 60 F. and the floor temperature falls below 72 F., the supplementary steam heat, from the coils |42, |43, |44, is placed under the control, in the first instance, of licor thermostat 12A, which, in turn, places the supplementary steam heat under the control of floor thermostats 12B, 1.|A, and 60A.

If the floor temperature is below 72 F., but above 71 F.. steam is provided to coil |42 only under control of tube 12B and valve |36.

If the floor temperature falls below 71 F.,

steam is provided to the floor coil |43 under the control of tube 1 IA and valve |31.

Coil |4| is under the further control of a thermostatic valve |45, which will not open until the temperature of the air passing over the supplementary thermostatic control bulb |46 is below a selected temperature. As long as the temperature of the air passing over the reheat coil |01 is suillclently high, the supplementary steam coil |4| will not function, the valve |35 being closed. If the reheat coil supplies insuilicient heat to the car, then bulb |46 will open valve |35 and permit The above addition of supplementary steam is accomplished because the circuit through tube 60 is opened by the outside temperature being below 60 F.. while the circuit through tube 12A is opened because the floor temperature of the car is below 72 F. This condition energizes relay E, with the consequent opening of the contacts E|,

E-2 and E-3. Contact E-i cuts off current to valve |35. This valve opens when its heating coil ceases to be energized, due to the opening of the electric circuit therethrough, thus providing steam to the coil |4| as previously described. The opening of contact E-Z places thermostat 12B in control of the valve |35. The opening of the circuit through 12B energizes relay F, with the consequent opening of contact F-i and deenergization of the heating element in valve |36. This deenergization of valve |36 permits the valve to open and provide steam to coil |42. The opening of contact E-3 places valve |31 under the control of floor thermostat 1 IA. If the floor temperature should fall below 71 F., the opening of circuit through thermostat 1| energizes relay K, with the consequent opening of contacts K-l, deenergization of valve |31. Opening of valve |31 and the supply of steam to coll |43.

From the above, it is to be seen that, when the outside temperature is below 70 F., but above 60 F., the general inside temperature of the car tends to be raised to a range between 74 F. and 75 F. and the iloor temperature tends to be maintained between 71 F. and 72 F., thus producing comfort conditions at all levels in the car.

Operation when outside temperature is below F.

When the outside temperature falls below 10 F., the control of the air conditioning system is placed under the control of inside thermostats 18 and 19, with the same floor heat control previously described.

The above results are produced by the opening of circuit through tube I0, with the consequent energization of relay D which, in turn, opens contacts D-|, D-2 and closes contacts D-3. The closing of contacts D-3 closes circuit in the same manner as if mercury tube 90 were closed, with the consequent deenergization of relay C, and the consequent placing of contacts C| through C-6 in the deenerglzed position. The circuits through tubes 10 and 80 are open due to the low outside prevailing temperature. With circuit through tube 90 closed, thermostats 18 and 19 are in control of the refrigerating system. if it is being operated, and the reheat coil |01, while the control of the supplementary steam continues exactly in the same manner as has been previously described.

It is to be understood that, ordinarily, the refrigerating system will have stopped long before any outside temperatures reach 10 F. or below; but on certain north and south railroads, cars frequently operate between extreme outside temperature conditions and, therefore, it may be convenient to continue operation of the refrigerating system at all times.

OPERATION WHEN CAR Is 1N YARD When the car is idle and is placed in the yard. or under similar conditions, it is generally desirable to stop the operation of the Diesel engine, and provide for a certain amount of oor heat. The floor heat will be suilicient to prevent freezing of the equipment on the car. This is accomplished by placing the engine control 48 in the "oi position. The control |48 is mechanically interlocked with switches |49 and |50 in such a manner that switches |49 and |50 are closed when |48 is in the off" position, but are opened when the control 48 is either on the Diesel or motor positions. When the switches |48 and |50 are closed, the valves |36 and |31 are energized,

thus closing them and preventing a supply of steam to coils |42 and |43.

If the floor temperature should fall below 60 F., the control l60A opens and energizes relay L, which. in turn, opens contacts L|, with the consequent deenergization and opening of solenoid valve |38. The opening of valve |38 supplies steam to floor coil |44, which is just large enough to heat the car to prevent freezing of the equipment.

STARTING CONTROL 0F THE DIESEL ENGINE The Diesel engine is controlled and started by moving the control |48 to the "Diesel position. While the engine is in idle condition, contacts 5| are open, thus deenergizing relay H and permitting contacts H-I to be closed. This produces a. circuit through the starter |08 and cranks the engine. At this time, the fuel valve |34 is energized and opened to supply fuel to the engine. If the temperature of the engine is above 40 F., the engine will start upon being cranked. When suflicient speed has been attained, the pressure in the wind box ||6 rises to operate control ||8 and close contacts |5|. The closing of contacts 5| energizes relay H and moves contacts H-I to the upper position, thus opening the circuit to the starter and simultaneously closing the circuit to solenoid valve |33. Solenoid valve |33 supplies air to the pneumatic clutch ||9 and connects the engine |05 to the generator 20.

At this time, the relay G being unenergized, contacts. G--I and G--Z are in their lower position. The generator |20 has its field winding |52 energized through G--I and the carbon pile |53 of the voltage and current regulator |54. A series coil |55 and a shunt coil |56 control the contact |51 in the Well known manner, so that when the voltage across the terminals of the generator is at the proper value in relation to the battery voltage, contacts |51 are closed; but are maintained open if the generator voltage is not suillciently high. The current and voltage regulator |54 includes a current coil |58 and a Voltage coil |59. which tend to increase the resistance of carbon pile |53 when either the current or voltage exceeds their respective safe limits.

A manually adjustable resistance R is provided for varying the eiect of coil |58 to regulate the output of the generator, as is well understood.

If the temperature of the engine should be below 40 F., a supplementary air heating means is provided for the engine, to insure starting thereof. For this purpose, a thermostat |60 conveniently may be placed in the water jacket, and when this is below 40 F., it closes contacts I6 When the control 48 was moved to the Diesel" position, relay O was energized, with the consequent closing of contacts O-|. Contacts O-l and 6| being closed, and contacts |62 being normally closed under the tension of spring |63, current is provided through the vibrator |64 to the transformer |65 and spark plug ||1 to produce ignition in the Wind box H6. At the same time, the supplementary fuel pump ||5 is energized and supplies fuel simultaneously to the wind box ||6. The fuel is ignited by the spark plug and heats the air before the same is supplied to the cylinders of the engine, thus insuring starting of the engine under cold conditions.

A suitable timing mechanism is provided for cutting off the supplementary air heating means after the proper time interval. Conveniently.

this may include a thermostatic resistance |66 which closes upon contact |61 after the proper interval of time. The closing of this circuit energizes holding relay |68, which maintains contacts |62 open as long as this circuit is maintained energized by contacts O-I or |6|, thus preventing further supply of fuel to the wind box H6. After the engine has been in operation a short time, the water temperature rises above 40 F., at which time contacts IBI are opened, thus deenergizing the supplementary fuel circuit for the remainder of the operating time of the engine.

OPERATION oF THE D. C. Moron It is necessary for certain railroads to stop operation of the Diesel engine, yet at the same time it is desirable to provide air conditioning for the car. Such conditions occur at terminals where the fumes of the internal combustion engine might be harmful. Under these conditions, the compressor may be driven by the generator |20 acting as a motor, and reheat, if necessary, will be supplied by the steam coil |4I.

To accomplish this motoring operation, the control |48 is moved to the motor position. When so moved, the control |48 energizes relay G, thus moving contacts G-|, G-2, G-3 to the energized position. The opening of the contacts G-|. and G-2 changes the field winding |52 of the generator to a motoring winding, since contact G-I moves to the upper position where it places winding |52 in series with the supplementary resistance |69. 'I'he closing of contacts G-3 opens solenoid valve |3| to permit steam to be available to coil 4| under control of valve |45 and bulb |46. The by-pass through valve 3| may, however, be extended to include bypassing of valve |45 and this arrangement will permit coil |4|l to act as a reheat coil in the same manner as coil |01. Under these conditions, valve |3| is energized at the same time that reheat coil |01 previously was energized when the system was operating under Diesel power. When the control |48 was moved to the motor position, the motor starter relay was energized to move the contact |1|, under the control of a time delay device |12, to sequentially close the contacts |13 to gradually throw out resistance |14 until normal motoring operation is obtained.

During motoring operation, the refrigeration system and the auxiliary steam coil |4|, now acting as a reheat coil, are under control of the same set of temperature responsive thermostat tubes as when on Diesel operation. Refrigeration alone, refrigeration with reheat, or heating alone may be obtained in the same manner as before.

SUMMARY oF OPERATION or' SYSTEM The operation of the air conditioning system is regulated by means of temperature responsive controls positioned within the car, which controls are modified in their operation by the temperature outside the car. When the outside temperature is suiciently high to require a reduction of the temperature of the air inside the car below the temperature outside the car, the air conditioning system is so regulated as to provide a gradual increase of inside temperatures when the outside temperature increases; the inside temperature, however, increases at a much slower rate than the outside temperature. Also. when the outside temperature falls sufllciently low, the air conditioning system will supply heat to the air either from the water system of the internal combustion engine or the usual steam supply on the train, or both. On cold days, higher inside temperatures are produced than on mild days. At all times, however, both refrigeration and heating systems may be rendered effective by the inside temperature controls, regardless of the temperature outside the car.

On the warmest days, the air is cooled by the evaporator |02 alone. When the outside temperature falls to a less warm zone, evaporator |02 is operated, but its effect is counter-balanced in part by the reheat coil |01. Then, as the outside temperature falls into a cold zone', the air is heated by reheat coil |01 alone, or supplemented by steam coil |4I, it being understood that under all conditions, the eiect of heat or refrigeration is always available to temper the eiect of the other.

When the outside temperature is 90 F., or above, refrigeration is produced in evaporator |02 and, if necessary, reheat is provided. The inside controls 19 and 18 are placed in command of the air conditioning system and tend to maintain the temperature inside the car between 79 F. and 78 F.

When the outside temperature is at 80 F., but below F., refrigeration is produced, with or without necessary reheat; but the air conditioning system is placed under the control of inside mercury tubes 14 and 15, with a consequent tendency to maintain the temperatures inside the car between 74 F. and 75 F.

When the outside temperature is at or above 70 F., but below 80 F., refrigeration is produced with or without reheat with a tendency to maintain inside temperatures between 71 F. and 72 F. under the control of tubes 1| and 12.

When the outside temperature is below 70 F., but above 60 F., the air conditioning system is placed under the control of inside thermostats 14, 15, and the reheat coil |01 and evaporator 02 are controlled in a manner tending to maintain the inside temperature between 74 F. and 75 F.

When the outside temperature falls below 60 F., but is still above 10 F., the evaporator 02 and reheat coil |01 continue under the control of inside thermostats 14, 15; but in addition. supplementary heat may be provided at the coil |4| and the iloor heat coils |42, |43 and |44.

When the outside temperature falls below 60 F. and the oor temperature falls below 72 F., the supplementary steam heat, from the coils |42, |43, |44, is placed under the control, in the rst instance, of floor thermostat 12A, which, in turn, places the supplementary steam heat under the control of floor thermostats 12B, 1|A, and 60A.

When the outside temperature falls below 10 F., the control of the air conditioning system is placed under the control of inside thermostats 18 and 19, with the same floor heat control previously described.

' When the car is idle and is placed in the yard. or under similar conditions, it is generally desirable to stop the operation of the Diesel engine, and provide for a certain amount of iloor heat.

If the iioor temperature should fall below 60 F., the control 60A opens and energizes relay L, which, in turn, opens contacts L|, with the consequent deenergization and opening of solenoid valve |38. The opening of valve |38 supplies steam to oor coil |44, which is just large enough to heat the car to prevent freezing of the equipment.

It is to be understood that the temperatures used throughout the specification are for purposes of illustration only, and that temperatures other than those selected can be used without varying the scope of the invention.

While the form of embodiment of the invention herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Air conditioning apparatus for a vehicle comprising in combination, a refrigerating system having an evaporator, a compressor and a condenser connected in refrigerant flow relationship, an internal combustion engine for operating said compressor, means using waste heat from said engine for reheating air cooled by said evaporator, temperature responsive means for controlling the flow of refrigerant to said evaporator, and means for flowing liquid refrigerant in thermal exchange with a portion of said compressor when said temperature responsive means indicates that no cooling of the air for said vehicle is required.

2. In combination, a heating system comprising an engine and heat dissipating means associated therewith, a cooling system comprising an evaporator, compressor and condenser connected in refrigerant flow relationship, means for circulating air within an enclosure in heat transfer relationship with said heating and cooling means, a generator driven by said engine, electrically operated thermostatic regulating means energized from said generator and adapted to maintain a selected temperature within the enclosure, said regulating means comprising a plurality of thermostats selectively operative to control the fioW of heat from the engine to the enclosure, and a plurality of thermostats selectively operative to control the refrigeration system, said thermostats providing a plurality of temperature ranges in which heating and cooling can be obtained, and means outside the enclosure comprising a plurality of thermostats for selectively determining which of the temperature ranges of the inside thermostats shall be active according to prevailing outside temperatures.

3. In combination, a heating system comprising an engine and heat dissipating means associated therewith, a cooling system comprising an evaporator, compressor and condenser connected in refrigerant ow relationship, means for circulating air within an enclosure in heat transfer relationship with said heating and cooling means, electrically operated thermostatic regulating means adapted to maintain a selected temperature within the enclosure, comprising a plurality of thermostats selectively operative to control the ow of heat from the engine to the enclosure, and a plurality of thermostats selectively operative to control the refrigeration system, said thermostats overlapping in their control functions to provide a plurality of temperature ranges in which either heating or cooling or cooling plus heating can be obtained, and means outside the enclosure comprising a plurality of thermostats for selectively determining which of the temperature ranges of l) B2i iilii l (Jil the inside thermostats shall be active according to prevailing outside temperatures.

4. In combination, means for cooling air for an enclosure, means for heating the air cooled by said first named means when said first named means has excess cooling capacity, means for heating the air adjacent the floor of said enclosure, means responsive to the temperature within said enclosure for controlling said cooling means, said heating means, and said floor heating means, and means responsive to the outside temperature to prevent the operation of said fioor heating means when the outside temperature is above a predetermined value.

5. An air conditioning system for an enclosure comprising in combination, a heating system and a cooling system for either simultaneously or independently conditioning air for said enclosure, means to supply supplementary heat to said enclosure to augment the capacity of said heating system, means responsive to temperature conditions within said enclosure for turning on said heating system while said cooling system is in operation, means responsive to temperature conditions within said enclosure controlling said cooling system, means responsive to temperature conditions outside said enclosure for modifying the effective operating temperature range of said heating and cooling systems, apparatus responsive jointly to temperature conditions inside and outside said enclosure controlling said supplementary heat so as to turn on said supplementary heat when both the inside temperature and the outside temperature indicate the necessity for supplementary heat and for turning off the supplementary heat when either the outside temperature or the inside temperature indicates that no supplementary heat is required.

6. Air conditioning apparatus for a vehicle comprising in combination, a refrigerating system having an evaporator, a compressor and a condenser connected in refrigerant flow relationship, an internal combustion engine for operating said compressor, means using waste heat from said engine for reheating air cooled by said evaporator. temperature responsive means for controlling the now of refrigerant to said evaporator, and means for flowing liquid Irefrigerant in thermal exchange with a portion of said compressor when said temperature responsive means indicates that no cooling of th'e air for said vehicle is required, said means for flowing liquid refrigerant in thermal exchange with a portion of said compressor comprising means for bypassing said evaporator.

7. Air conditioning apparatus comprising in combination, a refrigerating system having an evaporator, a compressor and a condenser connected in refrigerant flow relationship, an internal combustion engine for operating said compressor when cooling of the air is required and at times when no cooling of th'e air is required, valve means for preventing the flow of refrigerant to said evaporator, and means for flowing liquid refrigerant in thermal exchange with a portion of said compressor when said valve means prevents the flow of refrigerant to said evaporator.

8. In combination, a heating system comprising heat dissipating means, a cooling system comprising an evaporator, compressor and condenser connected in refrigerant flow relationship, means for circulating air for an enclosure in heat transfer relationship with said heating and cooling means, thermostatic regulating means adapted to maintain a selected temperature within the enclosure, comprising thermostatic means selectively operative to control thc ilow of heat from the heating system to the enclosure, and thermostatic means selectively operative to control the refrigeration system, said thermostatic means lapping in their control functions to provide a plurality of temperature ranges in which either heating or cooling o1 cooling plus heating can be obtained, and thermostatic means outside the enclosure for selectively determining which' of the temperature ranges of the inside thermostats shall be active according to prevailing outside temperatures.

9. In combination, a heating system comprising heat dissipating means, a cooling system comprising an evaporator, compressor and condenser connected in refrigerant flow relationship, means for circulating air for an enclosure in heat transfer relationship with said heating and cooling means, thermostatic regulating means adapted to maintain a selected temperature within the enclosure, comprising a plurality of thermostats selectively operative to control the iiow of heat from the heating system to the enclosure, and a plurality of thermostats selectively operative to control the refrigeration system, said thermostats overlapping in their control functions to provide a plurality of temperature ranges in which either heating or cooling or cooling plus heating can be obtained, and means outside the enclosure for selectively determining which of the temperature ranges of the inside thermostats shall be active according to prevailing outside temperatures.

10. In combination, a heating system comprising an engine and heat dissipating means associated therewith, a cooling system comprising an evaporator, compressor and condenser connected in refrigerant flow relationship, means for circulating air Within an enclosure in heat transfer relationship with said heating and cooling means, electrically operated thermostatic regulating means adapted to maintain a selected temperature within the enclosure, comprising thermostatic means selectively operative to control the flow of heat from the engine to the enclosure. and thermostatic means selectively operative to control the refrigeration system, said thermostatic means overlapping in their control functions to provide a plurality of temperature ranges in which either heating or cooling or cooling plus heating can be obtained and thermostatic means outside the enclosure comprising a plurality of thermostats for selectively determining which of the temperature ranges of the inside thermostats shall be active according to prevailing outside temperatures.

JAMES R. HORNADAY. 

